Vitamin K-along with Vitamins E,D and A- is one of the 4 lipophilic Vitamins needed in our bodies, to ensure optimal running of the system.
Roles:
- Its main role is in Hemostasis;the process of blood clotting/coagulation.
What Vitamin-K essentially does, is that it acts as a cofactor for reactions. This means, that it facilitates the action of a Carboxylase in the liver-which on its part adds a COO group to various clotting factors(CFs).
As a result, this modification enables the CFs, to react with phospholipids and calcium- allowing for their activation.
The affected CFs are: Factor II(Prothrombin), VII(Proconvertin), IX(Christmas Factor) and X(Stuart Factor).
- Another function of Vitamin K, is the activation of Osteocalcin in the bones.
Again through a COO substitution- modification is achieved- which results in the strengthening of bone-tissues, as a result of facilitated calcium uptake.
Minimum Requirement.
As is with all essential nutrients in our bodies, Phylloquinone also has a minimum requirement. This not only varies between the genders, but also between age groups.
- Until 10 years of age- circa 25 micrograms is required
- 10-15 years of age- circa 45 micrograms
- Men circa 80 micrograms; women circa 65 micrograms.
Sources.
Vitamin K can be found in all Green vegetables, especially Spinach. It is further found in foods such as Paprika, Cayenne, Chilli powder, Curry, Asparagus, Broccoli, Prunes, Brussels sprouts, Pickled cucumbers as well as Cabbages– to name but a few.
It is further produced by Intestinal bacteria in vivo, which explains the reason as to why under normal conditions, a deficiency is highly unlikely.
Deficiency.
A deficiency of Vitamin K, can however come into being, should the proximal and distal intestines be damaged, e.g in Crohn’s Disease, leading to an inability to absorb nutrients from the Gastrointestinal tract.
A further cause could be the overexposure of the Gut flora(intestinal bacteria) to antibiotics-hence their eradication. The in vivo Phylloquinone production is thus halted/ slowed down.(A reason as to why the intake of Antibiotica shouldn’t be overdone)
Excessive Aspirin, Tuberculostatica and Anti-epileptica intake, has also been known to cause a decreased Vitamin K absorption.
Symptoms.
With every deficiency-automatically comes a symptom. In the case of Vitamin K:
- Increased Haemorrhage–Nosebleeds, Blood in stool/urine, menorrhagia(heavy menstrual bleeding), prolonged waits before bleedings stop.
- Slowed bone-fracture healing.-Due to the reduced ability to absorb calcium.
- Diminished Cicatrisation-Slowed-down wound healing-a process directly related to blood clotting.
Vitamin K Antagonists:
Every plus side has its negative. Similarly, Phylloquinone has its antagonists, which help regulate its activity.
These are commonly put into use in medicine as prophylactic measures, in the event that the patient experiences excessive levels of coagulation e.g Thrombosis-which may lead to an infarction(Heart attack/stroke).
Common antagonists applied are Coumarin derivates such as Marcurmar and Warfarin. These inhibit the action of Vitamin K competitively,slowing the entire coagulation process.
An advantage of the usage of these antagonists, is the fact that their activity can be overrun, by simply increasing the bodily Phylloquinone intake.
More.
Important to note, is that the excessive intake of:
- Vitamin E(Tocopherol) inhibits the the Vitamin K dependent Carboxylase.
- Vitamin A(Retinol) inhibits Vitamin K absorption.
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